CURRENTS

CURRENTS; Prefabricated Circuitous Routes

By ELAINE LOUIE

Published: June 15, 1995

SOME people try to reinvent the mousetrap. Ace Architects, of Oakland, Calif., has reinvented the circular staircase.

A circular staircase is often mistakenly called a spiral staircase. In fact, a spiral staircase has a pole going up the middle, while a circular staircase is open and airy in the middle.

Unless the treads are very wide, spiral stairs are hard to walk on. "The treads come to a point at the pole, so the usable portion of the stair is restricted to the outside of the step," said David Weingarten, a partner in Ace. Circular stairs usually have a larger diameter and more tread area. "One can go up and down a circular stair more graciously, and you can carry things up and down the stairs," he said.

But spiral stairs are relatively cheap, because the components -- the pipe and treads -- are prefabricated. Single-flight staircases typically cost $4,000 to $5,000, he said; circular staircases cost $12,000 to $15,000, since most have to be custom-made.

What Ace has designed is a circular staircase that is mostly prefabricated and costs $6,000 for a single 10-foot flight. Mr. Weingarten and his partner, Lucia Howard, used a steel pipe, 3/8-inch thick and 3 feet in diameter, installing it in the house of a client and cutting out the unwanted steel with a torch. The staircase is supported by cantilevered steel beams that jut out from the wall and are hidden in the stair landings. Only the railing and the treads, which are carpeted plywood laid on steel plates, had to be custom-made.

Ace has installed five of the staircases -- four for one client, one for another -- and has a patent pending. Telephone: (510) 452-0775.